You may be able to put a setting circle on your mount. Telescope warehouse has them for like $3. I have a couple I got from them. 4” diameter. If you need a pic, I could post it if you would like.
Sure, show me a picture of it. I put a inclinometer on my Dob, to help me find objects, but the Tasco tube is plastic so it wouldnt work.
I am mainly concerned about the Tasco's optics for now, 30+ years hasn't been kind to them.